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        <h2><strong>ContactFilter</strong>
          class
        </h2>
        
<button id="show-inherited" class="show-inherited">Hide inherited</button>
<div class="doc">
<p>Implement a subtype of this class and pass it as the argument to
world.setContactFilter to provide collision filtering.
In other words, you can implement this class if you want finer control over
contact creation.</p>
<pre class="source">
class ContactFilter {
  ContactFilter();

  /**
   * Return true if contact calculations should be performed between these two
   * shapes.
   */
  bool shouldCollide(Fixture fixtureA, Fixture fixtureB) {
    final Filter filterA = fixtureA.filter;
    final Filter filterB = fixtureB.filter;

    if (filterA.groupIndex != 0 &amp;&amp; filterA.groupIndex == filterB.groupIndex)
      return filterA.groupIndex &gt; 0;

    return (filterA.maskBits &amp; filterB.categoryBits) != 0 &amp;&amp;
           (filterA.categoryBits &amp; filterB.maskBits) != 0;
  }
}
</pre>
</div>
<div>
<h3>Constructors</h3>
<div class="method"><h4 id="ContactFilter">
<button class="show-code">Code</button>
new <strong>ContactFilter</strong>() <a class="anchor-link" href="#ContactFilter"
              title="Permalink to ContactFilter.ContactFilter">#</a></h4>
<div class="doc">
<pre class="source">
ContactFilter();
</pre>
</div>
</div>
</div>
<div>
<h3>Properties</h3>
<div class="field inherited"><h4 id="runtimeType">
<button class="show-code">Code</button>
final Type         <strong>runtimeType</strong> <a class="anchor-link"
            href="#runtimeType"
            title="Permalink to ContactFilter.runtimeType">#</a>
        </h4>
        <div class="inherited-from">inherited from Object </div><div class="doc">
<p>A representation of the runtime type of the object.</p>
<pre class="source">
external Type get runtimeType;
</pre>
</div>
</div>
</div>
<div>
<h3>Operators</h3>
<div class="method inherited"><h4 id="==">
<button class="show-code">Code</button>
bool <strong>operator ==</strong>(other) <a class="anchor-link" href="#=="
              title="Permalink to ContactFilter.operator ==">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>The equality operator.</p>
<p>The default behavior for all <code>Object</code>s is to return true if and
only if <code>this</code> and 
<span class="param">other</span> are the same object.</p>
<p>If a subclass overrides the equality operator it should override
the <code>hashCode</code> method as well to maintain consistency.</p>
<pre class="source">
bool operator ==(other) =&gt; identical(this, other);
</pre>
</div>
</div>
</div>
<div>
<h3>Methods</h3>
<div class="method"><h4 id="ContactFilter">
<button class="show-code">Code</button>
new <strong>ContactFilter</strong>() <a class="anchor-link" href="#ContactFilter"
              title="Permalink to ContactFilter.ContactFilter">#</a></h4>
<div class="doc">
<pre class="source">
ContactFilter();
</pre>
</div>
</div>
<div class="method inherited"><h4 id="hashCode">
<button class="show-code">Code</button>
int <strong>hashCode</strong>() <a class="anchor-link" href="#hashCode"
              title="Permalink to ContactFilter.hashCode">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>Get a hash code for this object.</p>
<p>All objects have hash codes. Hash codes are guaranteed to be the
same for objects that are equal when compared using the equality
operator <code>==</code>. Other than that there are no guarantees about
the hash codes. They will not be consistent between runs and
there are no distribution guarantees.</p>
<p>If a subclass overrides <code>hashCode</code> it should override the
equality operator as well to maintain consistency.</p>
<pre class="source">
external int hashCode();
</pre>
</div>
</div>
<div class="method inherited"><h4 id="noSuchMethod">
<button class="show-code">Code</button>
<strong>noSuchMethod</strong>(String name, List args) <a class="anchor-link" href="#noSuchMethod"
              title="Permalink to ContactFilter.noSuchMethod">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p><code>noSuchMethod</code> is invoked when users invoke a non-existant method
on an object. The name of the method and the arguments of the
invocation are passed to <code>noSuchMethod</code>. If <code>noSuchMethod</code>
returns a value, that value becomes the result of the original
invocation.</p>
<p>The default behavior of <code>noSuchMethod</code> is to throw a
<code>noSuchMethodError</code>.</p>
<pre class="source">
external Dynamic noSuchMethod(String name, List args);
</pre>
</div>
</div>
<div class="method inherited"><h4 id="Object">
<button class="show-code">Code</button>
const <strong>Object</strong>() <a class="anchor-link" href="#Object"
              title="Permalink to ContactFilter.Object">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>Creates a new <code>Object</code> instance.</p>
<p><code>Object</code> instances have no meaningful state, and are only useful
through their identity. An <code>Object</code> instance is equal to itself
only.</p>
<pre class="source">
const Object();
</pre>
</div>
</div>
<div class="method"><h4 id="shouldCollide">
<button class="show-code">Code</button>
bool <strong>shouldCollide</strong>(<a href="../box2d_console/Fixture.html">Fixture</a> fixtureA, <a href="../box2d_console/Fixture.html">Fixture</a> fixtureB) <a class="anchor-link" href="#shouldCollide"
              title="Permalink to ContactFilter.shouldCollide">#</a></h4>
<div class="doc">
<p>Return true if contact calculations should be performed between these two
shapes.</p>
<pre class="source">
bool shouldCollide(Fixture fixtureA, Fixture fixtureB) {
  final Filter filterA = fixtureA.filter;
  final Filter filterB = fixtureB.filter;

  if (filterA.groupIndex != 0 &amp;&amp; filterA.groupIndex == filterB.groupIndex)
    return filterA.groupIndex &gt; 0;

  return (filterA.maskBits &amp; filterB.categoryBits) != 0 &amp;&amp;
         (filterA.categoryBits &amp; filterB.maskBits) != 0;
}
</pre>
</div>
</div>
<div class="method inherited"><h4 id="toString">
<button class="show-code">Code</button>
String <strong>toString</strong>() <a class="anchor-link" href="#toString"
              title="Permalink to ContactFilter.toString">#</a></h4>
<div class="inherited-from">inherited from Object </div><div class="doc">
<p>Returns a string representation of this object.</p>
<pre class="source">
external String toString();
</pre>
</div>
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